Weighted summing and radio frequency (rf) path selection for multiple antenna systems using sensors and received signal level

Abstract

Methods and apparatus are provided for intelligently enabling or disabling radio frequency (RF) paths in a wireless device. This may save power, for example, in situations where an RF path may not be contributing to antenna gain, but may still be drawing power from the device. One example method generally includes measuring received signal levels for a plurality of RF paths in an apparatus; powering off at least a portion of an RF path in the plurality if a received signal level of the RF path does not meet or exceed a threshold; after powering off the at least the portion of the RF path, determining that a signal blocking aspect affecting the RF path has been removed or at least reduced, without powering on the powered-off portion of the RF path for the determination; and powering on the powered-off portion of the RF path based on the determination.

What is claimed is: 
     
         1 . A method for wireless communications, comprising:
 measuring received signal levels for a plurality of radio frequency (RF) paths in an apparatus;   powering off at least a portion of an RF path in the plurality if a received signal level of the RF path does not meet or exceed a threshold;   after powering off the at least the portion of the RF path, determining that a signal blocking aspect affecting the RF path has been removed or at least reduced, without powering on the powered-off portion of the RF path for the determination; and   powering on the powered-off portion of the RF path based on the determination.   
     
     
         2 . The method of  claim 1 , wherein the determining comprises using one or more proximity sensors. 
     
     
         3 . The method of  claim 2 , wherein the one or more proximity sensors comprise one or more capacitive touch sensors. 
     
     
         4 . The method of  claim 2 , wherein each of the proximity sensors is located adjacent an antenna for each of the plurality of RF paths. 
     
     
         5 . The method of  claim 4 , wherein a first one of the proximity sensors is located on a first surface of the apparatus and wherein a second one of the proximity sensors is located on a second surface of the apparatus. 
     
     
         6 . The method of  claim 5 , wherein the first surface is opposite the second surface. 
     
     
         7 . The method of  claim 4 , wherein the signal blocking aspect degrades reception efficiency of the antenna for the RF path. 
     
     
         8 . The method of  claim 1 , wherein the signal blocking aspect comprises an effect due to a head or a hand of a user of the apparatus. 
     
     
         9 . The method of  claim 1 , further comprising:
 determining that the signal blocking aspect is above a level, wherein the powering off comprises powering off the at least the portion of the RF path in the plurality if the received signal level of the RF path does not meet or exceed the threshold and if the signal blocking aspect meets or exceeds the level.   
     
     
         10 . The method of  claim 1 , wherein the received signal levels comprise at least one of a carrier-to-noise ratio (C/N) or a received signal strength indicator (RSSI). 
     
     
         11 . An apparatus for wireless communications, comprising:
 a plurality of radio frequency (RF) paths; and   a processing system configured to:
 measure received signal levels for the plurality of RF paths; 
 power off at least a portion of an RF path in the plurality if a received signal level of the RF path does not meet or exceed a threshold; 
 determine, after powering off the at least the portion of the RF path, that a signal blocking aspect affecting the RF path has been removed or at least reduced, without powering on the powered-off portion of the RF path for the determination; and 
 power on the powered-off portion of the RF path based on the determination. 
   
     
     
         12 . The apparatus of  claim 11 , wherein the processing system is configured to determine that the signal blocking aspect has been removed or at least reduced by using one or more proximity sensors. 
     
     
         13 . The apparatus of  claim 12 , wherein the one or more proximity sensors comprise one or more capacitive touch sensors. 
     
     
         14 . The apparatus of  claim 12 , wherein each of the proximity sensors is located adjacent an antenna for each of the plurality of RF paths. 
     
     
         15 . The apparatus of  claim 14 , wherein a first one of the proximity sensors is located on a first surface of the apparatus and wherein a second one of the proximity sensors is located on a second surface of the apparatus. 
     
     
         16 . The apparatus of  claim 15 , wherein the first surface is opposite the second surface. 
     
     
         17 . The apparatus of  claim 14 , wherein the signal blocking aspect degrades reception efficiency of the antenna for the RF path. 
     
     
         18 . The apparatus of  claim 11 , wherein the signal blocking aspect comprises an effect due to a head or a hand of a user of the apparatus. 
     
     
         19 . The apparatus of  claim 11 , wherein the processing system is further configured to determine that the signal blocking aspect is above a level and wherein the processing system is configured to power off the at least the portion of the RF path in the plurality if the received signal level of the RF path does not meet or exceed the threshold and if the signal blocking aspect meets or exceeds the level. 
     
     
         20 . The apparatus of  claim 11 , wherein the received signal levels comprise at least one of a carrier-to-noise ratio (C/N) or a received signal strength indicator (RSSI). 
     
     
         21 . A method for wireless communications, comprising:
 measuring received signal levels for a plurality of radio frequency (RF) paths in an apparatus;   measuring signal blocking aspects of the plurality of RF paths using a plurality of proximity sensors; and   performing a weighted combination of signals received by the plurality of RF paths in an antenna diversity scheme based on the measured received signal levels and on the measured signal blocking aspects.   
     
     
         22 . The method of  claim 21 , wherein the plurality of proximity sensors comprises one or more capacitive touch sensors. 
     
     
         23 . The method of  claim 21 , wherein each of the proximity sensors is located adjacent an antenna in each of the plurality of RF paths. 
     
     
         24 . The method of  claim 21 , wherein a first one of the proximity sensors is located on a first surface of the apparatus and wherein a second one of the proximity sensors is located on a second surface of the apparatus opposite the first surface. 
     
     
         25 . The method of  claim 21 , wherein the signal blocking aspects comprise effects due to a head or a hand of a user of the apparatus. 
     
     
         26 . An apparatus for wireless communications, comprising:
 a plurality of radio frequency (RF) paths; and   a processing system configured to:
 measure received signal levels for the plurality of RF paths; 
 measure signal blocking aspects of the plurality of RF paths using a plurality of proximity sensors; and 
 perform a weighted combination of signals received by the plurality of RF paths in an antenna diversity scheme based on the measured received signal levels and on the measured signal blocking aspects. 
   
     
     
         27 . The apparatus of  claim 26 , wherein the plurality of proximity sensors comprises one or more capacitive touch sensors. 
     
     
         28 . The apparatus of  claim 26 , wherein each of the proximity sensors is located adjacent an antenna for each of the plurality of RF paths. 
     
     
         29 . The apparatus of  claim 26 , wherein a first one of the proximity sensors is located on a first surface of the apparatus and wherein a second one of the proximity sensors is located on a second surface of the apparatus opposite the first surface. 
     
     
         30 . The apparatus of  claim 26 , wherein the signal blocking aspects comprise effects due to a head or a hand of a user of the apparatus.